The prevalence of latent Equid herpesviruses in the tissues of 40 abattoir horses

Abstract
Summary: Equid herpesviruses 1 or 4 (EHV‐1 or −4) were isolated by co‐cultivation from 60% of 40 horses examined at slaughter. The lymph nodes draining the respiratory tract were the most common source of virus. EHV‐1 or EHV‐4 was never isolated from the trigeminal ganglia (SLG). The polymerase chain reaction (PCR) detected virus in 87.5% of bronchial lymph nodes and a similar level in the trigeminal ganglia that were examined. By both assays approximately one third of the positive animals harboured both viruses.Equid herpesvirus 2 (EHV‐2) was isolated from all but one of the horses and from >75% of the lymph nodes draining the respiratory tract; a viruses were isolated only in the presence of EHV‐2.The results indicate that latent EHV‐1 and EHV‐4 are widespread in the equine population and that the primary site of latency is the lymph nodes of the respiratory tract.